1. Technical Field
Embodiments of the present disclosure relate to cable modems, and more particularly to a ranging method of a cable modem.
2. Description of Related Art
Before allowing a computer to access the Internet, a cable modem needs to start up and connect to a cable modem terminal system (CMTS). This process can take a while. Thus, most computers are shut off when users complete using the computers, while cable modems are kept to be working to be used anytime.
Usually, most cable modems cannot be used 24 hours a day. Actually, most cable modems are only used during a particular time interval, such as from 6 pm to 10 pm a day. Once at work, the cable modems requires periodically executing ranging with the CMTS to keep communication with the CMTS every a few seconds, which wastes power.
However, if the cable modems are shut off when the cable modem is not at work, the cable modems will disconnect to the CMTS. Thus, this start-up process decreases satisfaction of the users. There remains a heretofore unaddressed need to overcome the limitations described.